This invention relates to electrical equipment enclosures in general, and in particular to an improved hinge for a rainproof electrical equipment enclosure.
Electrical equipment enclosures of the type to which this invention relates are made of sheet metal or heavy duty plastic or other materials and are usually designed to be mounted on walls or other vertical surfaces. They are intended to protect electrical equipment such as circuit breakers or switches from rain as well as protect people from the hazardous voltages on the equipment. This type of equipment enclosure typically consists of two main parts, a box assembly and a cover. The box assembly usually consists of two pieces rigidly fastened together, but may be formed from a single sheet of metal as described in U.S. Pat. No. 4,851,963. The top wall of this assembly is often referred to as the hood as it shields the enclosure from the entry of rain. The cover is hinged at the top, under the hood, and is lifted to permit access to the equipment within the enclosure.
The cover hinge mechanism often uses a pin that protrudes through one side of the box and the cover flange and a second pin that protrudes through the other side of the box and the cover. This arrangement has not been completely satisfactory since it requires a separate component, thus increasing the cost of materials and the man-hours required to assemble the enclosure.
Attempts have been made to eliminate the pin, for example, by punching a three sided hole in the box and folding the flap over to engage a matching hole in the cover flange. There were some problems with this arrangement because of tolerance of the parts in mass produced enclosures and because of difficulty in assembling the box and the cover at the factory.
Another attempt was to eliminate the pin and to punch an embossment or bump in the box or hood, again matching up with a hole in the cover flange. This was easier to assemble, but there were still problems with tolerances. If the tolerances were too close there would be binding; if the tolerances were too loose the cover would fall off.